<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>数据类型JS</title>
</head>
<body>
	


	<script>
		// var message = "some string";
		// alert(typeof message);
		// alert(typeof 99);
		// 
		// 
		// alert(null == undefined);
		// 
		var age = 11;
		var ageAsString = age.toString();
		alert(ageAsString);

	</script>
</body>
</html>